When a user interacts with a digital display, such as an organic light emitting diode (OLED) display panel, which may be part of a computer, tablet, or smart phone display, it may be advantageous to detect when a user touches the display or when a user's hand or finger is near the display. To provide high quality user interaction, it may be advantageous to detect the touch of one or more of the user's fingers, including the location of each contact point on the display. It may also be helpful to detect, separately and simultaneously, the proximity of one or more fingers, i.e., their presence in a volume in front of the display, which may be referred to as hover detection, and the location of each such finger, in three dimensions, relative to the surface of the display.
Existing methods of touch sensing in displays may use capacitive sensing or other techniques which may exhibit pre-touch, i.e., which may incorrectly report the touch of a human finger when the finger is near but not in contact with the display. Other methods based on optical sensing of fingers may be sensitive to ambient light. Moreover, existing techniques may have poor accuracy in estimating the distance of a finger from a display, and may lack the ability to reliably and accurately determine the respective positions of multiple fingers near a display. Thus, an improved system and method for detecting touch of, and proximity to, a display is needed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.